A music producer claims he's owed at least $24 MILLION for his work on the Paul Anka/Michael Jackson collaboration "This Is it" -- and now, he's suing Anka and the MJ Estate for the money.

The producer -- named Michael Jonzun -- filed the lawsuit in Massachusetts federal court, claiming he helped remake Paul and MJ's 1983 song "I Never Heard" ... into what eventually became MJ's 2009 song "This Is It."

According to the lawsuit, Jonzun owns one-third of "This Is It" but he never got paid his share of the song's proceeds -- so he's suing.

Paul Anka tells TMZ, he has never even heard the name Michael Jonzun before today -- and any claims Jonzun owns a portion of "This Is It" are "BS."

Since the 3rd anniversary of its release a few days ago, I've had a feeling that there would be a story relating somehow to This Is It on TMZ, also because it was the 3rd anniversary of thisisalsoit on October 29th. So I did a little :Michael_Jackson_dancing_smile when I saw this story, ESPECIALLY with the number 24 there considering the latest discussion on Sign 6

Paul Anka tells TMZ, he has never even heard the name Michael Jonzun before today -- and any claims Jonzun owns a portion of "This Is It" are "BS."

Right, BS it is, because according to Michael Jonzun´s biography he started on his own in ´85, 2 years after the collaboration between MJ and Paul Anka on this song, so Jonzun couldn´t have worked on the song. :suspect: